Forge version: 2501
Twilight Forest version: 3.2.177

Steps to reproduce:

1. Hit a Hydra head using a 40 attack sword or a 80 attack sword.

What I expected to happen: The 80 attack one will do less hit times than half of the 40 attack one because attack damage can reduce the effect of armor points.

What happened instead: The 80 attack one hit 13 times and the 40 attack one hits 25 times.

The Hydra does nothing special except dividing the damage by 8.
https://github.com/TeamTwilight/twilightforest/blob/1.12.x/src/main/java/twilightforest/entity/boss/EntityTFHydra.java#L608

Perhaps you hit the head with the 40 attack?

Yes. The glass sword.

Actually it seems the damage dealt to the hydra changes when hitting a head depending if the head mouth is open or not
https://github.com/TeamTwilight/twilightforest/blob/1.12.x/src/main/java/twilightforest/entity/boss/EntityTFHydra.java#L637-L642

Is this actually an issue then?

I hit the hydra only the mouth is closed
.

So the damage does not follow the 1.9+ armor rule is on purpose. In order to prevent player from hitting the body using high attack weapons?

I'm not even sure what this rule is, we delegate the damage to the super call. Everything else is handled by vanilla.

I think what's meant is that the damage values haven't been rebalanced to account for armor getting nerfed overall in 1.9

#285